Latest Wotlk patch, logging in always produces the below error

30x [string "Scrap/libs/TaintLess/Taint..."]:77: hooksecurefunc(): GetAttribute is not a function
[string "=[C]"]: in function `hooksecurefunc'
[string "Scrap/libs/TaintLess/TaintLess.xml:"]:77: in main chunk

Locals:

There's an update to that "TaintLess" library here:

https://www.townlong-yak.com/addons/taintless/release/23-05-18

I just tried replacing the TaintLess sub-folder inside libs with the version from that URL, and the error seems to go away.